This invention relates to prepayment utility meter systems, and more particularly to a more secure method and apparatus for communicating information between utility sales locations to customer sites using smart cards.
Utility companies have traditionally performed reading and rendering bills for collecting for electric, gas, and water or other utility services after such services have been used by a customer. More recently, prepayment utility metering systems have been proposed as a way for overcoming some of the shortcomings of traditional billing systems. These prepayment systems were designed so that the purchase of a supply of electricity, gas, or water is made at a central station such as the gas or electric utility office, and the information regarding the amount of the purchase is then communicated to the customer site where the utilities are consumed. At the customer site a metering device is installed which is designed to receive the prepayment communication information, and credit the user with the amount purchased at the central site. These types of proposed prepayment metering systems may reduce meter reading expenses, bad debt collection, account transfer expenses and credit department expenses, and may providing a greater awareness on the consumer""s consumption habits.
One of the problems with these prepayment utility systems is that they are difficult and costly to install. Typically the electric metering device is installed on an outside of a consumer or business location and a terminal which reads the prepayment information is either located with the meter or coupled by a cable to the meter and located inside. Installation requires routing the cable through the building. This is time consuming and expensive and in the case of existing consumer residences may require the consumer to be at home which is a further inconvenience and expense.
Another problem with typical prepayment utility systems is that they do not provide for communication of information back to the utility service provider. With these typical prepayment systems, an amount of credit is issued to a consumer and at the customer site. A customer terminal receives the credit and reduces the credit as the utility is consumed. The utility service provider has no way of knowing anything about the consumption at the consumer location. The utility service providers only know that a customer requests more credit and issues the credit to the consumer. For example the utility service provider does not know how the consumer is using that credit, where or on what utility meter the customer is using that credit, and also may be unaware of any remaining credit that exists on consumers cards. Furthermore the utility service provider has no way of knowing if there has been tampering with these cards.
Accordingly, what is needed is a prepayment energy metering system that is easier and less expensive to install in existing consumer locations. What is also needed is a prepayment energy metering system that provides information back to the utility service provider.
U.S. Pat. No. 5,146,067 entitled xe2x80x9cPrepayment Metering System Using Encoded Purchase Cards From Multiple Locationsxe2x80x9d, and U.S. Pat. No. 4,731,575 entitled xe2x80x9cPrepayment Metering System Using Encoded Purchase Cardsxe2x80x9d disclose prepayment metering systems and are hereby incorporated by reference.